Arrangements for treating and in particular analyzing a plurality of samples

ABSTRACT

ARRANGEMENT FOR TREATING A PLURALITY OF SAMPLES, COMPRISING A DISTRIBUTOR ADAPTED TO BE DRIVEN WITH ALTERNATE MOVEMENT BETWEEN A &#34;REST POSITION&#34; AND A &#34;WORKING POSITION,&#34; IN WHICH LATTER IT IS CAPABLE OF CARRYING OUT AT LEAST PART OF THE OPERATIONS ON ONE OF THE SAMPLES AT A FIXED STATION, AND A SUPPORT ON WHICH SAMPLES ARE DISTRIBUTED AT PREDETERMINED REGULAR INTERVALS, ADAPTED TO BRING EACH SAMPLE TO THE AFORESAID FIXED STATION IN SUCCESSION, WHEREIN THE SUPPORT CARRIES ABUTMENT ELEMENTS IN POSITIONS WHICH CORRESPOND RESPECTIVELY WITH THOSE OF THE SAMPLES AND THE DISTRIBUTOR CARRIES A ROCKING MEMBER ADAPTED TO REPEL, AT THE COST OF ITS INHERENT ROCKING ACTION FROM A POSITION OF EQUILIBRIUM, ONE OF THE AFORESAID ABUTMENT ELEMENTS TO PRODUCE A UNITARY MOVEMENT   OF THE PLATE EVERY TIME THE DISTRIBUTOR IS MOVED TOWARDS ITS WORKING POSITION, THE AFORESAID ROCKING ACTION BEING SUFFICIENT FOR SAID MEMBER TO BE ALBE TO ACT ON THE FOLLOWING ABUTMENT ELEMENT OF THE SUPPORT AFTER BEING RETURNED TO ITS POSITION OF EQUILIBRIUM AND IN THE COURSE OF THE FOLLOWING ALTERNATE MOVEMENT OF THE DISTRIBUTOR.

1971 JEAN-CLAUDE CREPIN 3,623,331

ARRANGEMENTS FOR TREATING, AND IN PARTICULAR Filed Dec. 16, 1969ANALYZING, A PLURALITY OF SAMPLES JEAN CLAUDE CREPIN INVENTOR 0 BY J NSUnited States Patent rm. c1. nis 17/00 US. Cl. 74822 9 Claims ABSTRACTOF THE DISCLOSURE Arrangement for treating a plurality of samples,comprising a distributor adapted to be driven with alternate movementsbetween a rest position and a working position, in which latter it iscapable of carrying out at least part of the operations on one of thesamples at a fixed station, and a support on which the samples aredistributed at predetermined regular intervals, adapted to bring eachsample to the aforesaid fixed station in succession, wherein the supportcarries abutment elements in positions which correspond respectivelywith those of the samples and the distributor carries a rocking memberadapted to repel, at the cost of its inherent rocking action from aposition of equilibrium, one of the aforesaid abutment elements toproduce a unitary movement of the plate every time the distributor ismoved towards its working position, the aforesaid rocking action beingsufficient for said member to be able to act on the following abutmentelement of the support after being returned to its position ofequilibrium and in the course of the following alternate movement of thedistributor.

This invention relates to arrangements for treating, and in particularanalyzing, a plurality of samples, of the kind comprising, on the onehand, a device referred to hereinafter in a general manner by the termdistributor, which is adapted to carry out at least part of theoperations of treating or analyzing each sample at a fixed station, and,on the other hand, a support adapted to go through movements by discretevalues or unitary movements enabling it to bring successive samples upto said station (it being understood that the word sample indicates anytreatment unit such as a container, cup or cell or the like, thecontents of which can be withdrawn, made up or treated in any othermanner through the medium of the distributor); and it relates moreparticularly, in one of its preferred applications, to an arrangementdesigned to permit automatic analysis by chromatography, moreparticularly the automatic introduction of successive samples, forexample amino acids, into a chromatography column filled with ionexchange resin.

Arrangements of this kind are already known, in particular automaticarrangements, in which the movement of the support is dependent on thatof the distributor or vice versa. The known arrangements, however, aregenerally characterized by great complexity to enable the manyconditions which must be complied with for satisfactory operationthereof to be constantly fulfilled. For example, the support must not gothrough more than one unitary movement each time it is operated by thedistributor and must moreover be locked at least during the time whenthe appropriate operations are being carried out by the distributor onthe sample which is at aforesaid fixed station at the time; on the otherhand, the distributor must not be able to reach its working position orbegin the execution of one of the aforesaid operations automatically ifthe support has not previously gone through a complete unitary movement,etc.

The object of the invention is therefore, above all, to render thesearrangements such that they meet the various requirements in practicebetter than heretofore, in particular as regards both the simplicity andthe reliability of control of the unitary movements of the supportcarrying the treatment units.

The arrangement according to the invention, which comprises adistributor adapted to be driven with alternate movements between a restposition and a working position, in which latter it is capable ofcarrying out at least part of the operations on one of the samples at afixed station, and a support on which the samples can be distributed atpredetermined regular intervals and adapted to go through unitarymovements enabling each of these samples to be brought up to theaforesaid fixed station in succession, is characterized by the fact thatthe support carries abutment elements in positions which arerespectively in correspondence with those of the samples and thedistributor carries a member adapted to rock in the direction ofmovement of the support from a position of equilibrium in which it isdisposed, more particularly when the distributor is at rest, to a givenoff-set position, and to repel, at the cost of its inherent rockingaction, one of the aforesaid abutment elements to produce a unitarymovement of the plate every time the distributor is moved towards itsworking position, the aforesaid rocking action being sufficient for saidmember to be able to act on the following abutment element of thesupport after being returned to its position of equilibrium and in thecourse of the following alternate movement of the distributor.

In a preferred constructional form of this arrangement, the distributorperforms its reciprocating movements in a vertical direction and thesupport is constituted by a circular plate adapted to go through unitaryangular movements about its axis, the samples being disposed on radii ofsaid circular plate at respectively equal distances from the centrethereof, the driving elements being constituted by pegs projecting atthe periphery of the plate and extending the aforesaid radii, therocking member being constituted by a lever pivoting about a pin andhaving an inclined surface acting on the corresponding peg on thedescent of the distributor.

The rocking member is advantageously carried by a part mounted on thedistributor through the medium of resilient means, said part coming intoabutment with a fixed part of the arrangement before the distributor hasreached its working position, the distributor being then only able tocomplete its travel in opposition to the action of the aforesaidresilient means.

The invention can be clearly understood in any case with the aid of thefollowing additional description and of the accompanying drawing, whichadditional description and drawing are, of course, given above all byway of indication.

FIG. 1 of the drawing shows in perspective part of an arrangement forthe automatic treatment of a plurality of samples;

FIGS. 2 and 3 are enlarged elevational views of one of the parts of thearrangement of FIG. 1 in two positions which it is capable of adoptingin the course of the operation thereof.

An arrangement in accordance with a preferred construction form of theinvention and designed to permit automatic analyses by chromatography,more particularly the automatic introduction of successive samples, forexample of amino acids, into chromatography columns filled with ionexchange resin, may be constituted more particularly as follows.

First of all, with regard to this arrangement considered as a whole, itcomprises:

A sample support constituted, for example, by a circular plate 1 adaptedto be driven with unitary angular movements about its axis and having aseries of orifices 2 disposed, for example, in two concentric circularrows 2a and 21; on radii of this circular plate and defining seats fortreatment units, for example cups or cells 4a and 4b containing thesamples to be analysed, the unitary movements having the eifect ofbringing each of these cups or cells up to a given fixed station insuccession; and

A distributor designated as a whole by the reference 3 and adapted to bemoved vertically and alternately between a rest or inoperative position(such as that represented in FIG. 1) and a working position at the levelof the aforesaid fixed station, in which position the distributor iscapable of carrying out an operation, the cups 4a, 4b located on thesame radius of the circular plate 1 being situated at that instant atthis fixed station perpendicularly below the distributor.

To this end, the distributor, which is preferably electropneumaticallycontrolled, includes a jack 6, a compensating system (not shown)enabling the rate of descent of the jack to be regulated, and two parts7a and 7b participating in the execution of the aforesaid operation onthe samples contained in the cups 4a, 4b.

In the particular application considered, these parts 7a, 7b formelution heads made, for instance, of plastics material knowncommercially by the name of Kel-F; they are disposed at the end of theshaft of the jack and symmetrically with respect thereto, each of theseparts being provided with an axial duct opening at the bottom and beingprovided with a coupling 8a or 812, for example of the type known by thename Swagelock, connecting the corresponding axial duct to an elutionpump (not shown) through the medium of a polyethylene tube 9a or 9b.

When the distributor is in its working position, the elution heads 7a,7b are applied to the tops of the cups 401 and 45, respectively, theelution pumps aforesaid being then able to introduce measured amounts ofeluent in manner known per se into the cups 4a, 41) through the mediumof the tubes 9a, 9b and the elution heads 7a, 7b. In the particularapplication considered, the cups 4a, 4b carried by the plate are piercedat their base, the samples of amino acids to be subjected to analysisbeing then adsorbed on a resin. In their working position, the cups 4a,4b then communicate in manner known per se with two hollow parts (notshown), for example of Kel-F material, disposed below the circular plateand respectively communicating with the heads of two chromatographycolumns (not shown) and machined in such manner that the cups areapplied intimately against them when the elution heads 7a, 7b bear onthe tops of the cups 4a, 4b.

The successive cups 401, 4b can then be brought respectively up to theaforesaid fixed station by unitary angular rotary movements of theplate 1. Each of the concentric rows 2a, 2]; comprises, for instance,forty seats 2, so that forty pairs of samples can be treated insuccession by bringing them successively to the fixed working station byunitary rotary movements through an angle of 9 According to theinvention, the mechanical drive of the circular plate 1 for causing itto go through the angular movements respectively equal in the exampleconsidered to an angle of 9 is effected through the medium of a partreferred to as a whole by the reference 11, carried by the distributor 3and adapted to engage with the support in such manner that it producesan angular movement of the plate when the distributor is brought fromits rest position to its working position, the distributor being able toattain this latter position only if the plate has undergone a completeunitary rotation.

More particularly, level with each group of cups 4a, 4b, the circularplate has elements 12 preferably constituted by pegs mounted at theperiphery of the plate and co-operating with a movable member 13 of thepart 11 on the descent of the distributor into its working position, theengagement being accompanied by a displacement of the member 13 itselfwith respect to its inherent rest position, this displacement beingsufficient to enable it to engage with the following peg when saidmember has found its position of equilibrium again and on a freshdescent of the distributor.

The movable member 12 aforesaid is advantageously constituted by apivoting lever adapted to pivot about a pin 14 fast with the part 11 andhaving an inclined surface 16 which, when the distributor is in its restposition, is located perpendicularly above the peg 12 corresponding tothat one of the treatment units which is then at the aforesaid fixedstation. The angular movement (in the direction of the arrow 17 whichcan be seen in FIG. 2) of the plate 1 (the relative position of whichwith respect to the part 11 is shown by chain-dotted lines in FIGS, 2and 3) is obtained by the sliding action which is imposed on the peg 12by the inclined surface 16 on the descent of the part 11 with thedistributor 13 towards the working position of the latter. The positionof the pin 14 with respect to the inclined surface 16 of the lever 13 issuch that this lever is impelled to rock after engagement from itsinherent position of equilibrium (or position of rest on a surface 18 ofthe part 11) into a different ofi-set position (shown in FIG. 3) underthe effect of the thrust exerted on the peg by the inclined surface ofthe lever, this rocking action being sufficient for said inclinedsurface to be located once more perpendicularly above the following peg12a when the distributor and the part 11 have been brought back intotheir respective rest positions.

FIG. 2 shows the position of the lever 13 at the instant when it acts onthe peg 12 which is perpendicularly below it in the course of thedescent of the distributor 3, and FIG. 3 shows the aforesaid differentoff-set position of the lever 13 (in abutment with a surface 19 of thepart 11) at the end of the downward travel of the part 11.

Having returned to its position of equilibrium following the ascent ofthe distributor, the lever 13 will then be perpendicularly above thefollowing peg 12a and when, in the course of the following descent ofthe distributor, it acts on this peg 12a, it is in the position shown inchain-dotted lines in FIG. 3.

The rocking of the lever 13 in the course of its action on a peg 12 isobtained automatically if the relative initial and final positions(shown in FIGS. 2 and 3, respectively) of the inclined surface 16 and apeg 12 are on each side of the vertical 21 (shown chain-dotted in FIG.2) passing through the pivot 14 0f the lever. The automatic return ofthe lever 13 to its inherent rest position is easily obtained if thisrocking is accompanied by a relative raising of the centre of gravity ofthe lever 13, which can be achieved by giving the part 13a, which isadapted to come into contact either with the abutment surface 18 or withthe abutment surface 19, a sufficient length from the pivot 14.

The arrest of the lateral movement of the peg 12 urged by the lever 13is controlled by the arrest of the descending movement of the part 11itself, it being possible to obtain this arrest by the abutment of itsbase 22 against a fixed part, for example the pedestal 23 (FIG. 1)supporting the plate 1. According to an advantageous supplementarycharacteristic of the invention, the part 11 is normally held in a fixedrelative position, in particular in a low position, with respect to thedistributor 3 through the medium of resilient means such as a spring 24,the assembly consisting of the distributor 3 and the part 11 beingarranged in such manner that the part 11 immobilizes the plate 1 beforethe distributor has itself completely finished its descending travel.The completion of this descending travel, resulting in the applicationof the elution heads 70, 7b against the cups 4a, 4b, is then effected atthe cost of a compression of the spring 24.

As a result of which there is obtained an extremely simple system ofdirect mechanical rependence of the angular rotary movements of theplate on the alternating movements of the distributor 3. This system ismoreover prefectly reliable. Assuming, in fact, that the actuation ofthe elution pumps is automaticaly dependent on the application of theelution heads 7a, 7b to the cups 4a, 4b, it becomes impossible tointroduce given volumes of eluents into the same cups accidentally twoor more times. In fact, the distributor 3 can descend into its workingposition only if the plate has effected a unitary angular movement inconcomitant fashion. Accidental locking of the plate prohibits inparticular (through the medium of the part 11 and the lever 13) thecontinuation of the descent of the distributor 3, and, consequently, thecontinuation of the automatic analysis cycle. Moreover, the lower end13b of the lever 13 prevents the plate effecting more than one unitarymovement (as a result of the resultant abutment of the peg 12a againstthe lower end 13b of the lever 13).

Moreover and by construction, the part 11 always brings the elutionheads and the cups into coincidence, without it therefore beingnecessary to effect periodic adjustments of the arrangement.

Furthermore, due to the spring 24, the final pressure of the distributoris applied only to the cups, so that the assembly can be subjected toconsiderable operating pressures, for example pressures of 70 kg./crn.in particular when the pneumatic system which has just been described isemployed, as a result of which leakages need not be feared.

The arrangement according to the invention may therefore, for example,operate as follows.

An electric pluse delivered to the electropneumatic control device ofthe jack produces the descent of the distributor 3; the lever 13 of thepart 11, which is initially in its rest position (FIG. 2), acts on thepeg 12 which is perpendicularly below its inclined surface 16 andcompels it to move in the direction of the arrow 17 while the descent ofthe distributor 3 continues; this co-operation of the inclined surface16 and the peg 12 in question in the course of the descent of the jack 6produces the rocking of the lever 13 at the latest when the peg 12passes perpendicularly below the pivot 14; the angular movement of theplate is interrupted when the base 22 of the part 11 encounters thepedestal 23, the lever 13 and the aforesaid peg 12 then occupying therelative positions shown in FIG. 3. The distributor then completes itstravel, compressing the spring 24, until the instant when its elutionheads 7a, 7b are applied against the cups 4a, 4b; the elution pump isthen able to supply given volumes of eluents to the cups 4a, 4b throughthe tubes 9a, 9b and the elution heads 7a, 7b; at the end of the cycleof elution of the amino acids and after the arrest of the elution pumpsanother pulse is delivered to the control device of the electropneumaticjack and this then reverses the compressed air circuit, thus causing theascent of the jack. The lever 13 then returns to its rest position; andend-of-travel contact actuated when the distributor reaches is restposition produces a second electric pulse which is used to produceautomatically a fresh descent of the distributor and the exchange ofsamples under the conditions which have been described hereinbefore.

As is obvious and as is moreover already apparent from the foregoing,the invention is by no means limited to those methods of applicationthereof or to those constructional forms of its various parts which havebeen more particularly indicated; on the contrary, it covers allvariants thereof.

What is claimed is:

1. A device for treating a plurality of samples, comprising adistributor adapted to be driven with alternate movements between a restposition and a working position, in which latter it is capable ofcarrying out at least part of the operations on one of the samples at afixed station, and a support on which the samples can be distributed atpredetermined regular intervals, the support being adapted to bedisplaced by specific amounts to enable each of these samples to bebrought up to the aforesaid fixed station in succession, wherein theimprovement comprises abutment elements carried by the support inpositions which correspond respectively with those of the samples and amember carried by the distributor disposed in a position of equilibriumrelative to said distributor and out of contact with any of saidabutment elements when said distributor is at rest, said member adapedto rock in the direction of movement of the support from a position ofequilibrium in which it is disposed when the distributor is at rest, toa given off-set position, said member being further adapted when saiddistributor is moved towards its working position to meet and repel oneof the aforesaid abutment elements and to undergo a rocking in thedirection of movement of the support to an off-set position relative tosaid distributor, as a result of this repelling action and of saidmotion of said distributor, to produce a unitary movement of the supportevery time the distributor is moved towards its working position, theaforesaid rocking action being sufficient for said member to be able tomeet and act on the following abutment element of the support afterbeing returned to its position of equilibrium and in the course of thefollowing alternate movement of the distributor.

2. Device according to claim 1, wherein the distributor can be movedalternately from its rest position to its working position in a verticaldirection.

3. Device according to claim 2, wherein the rocking member carried bythe distributor comprises a lever pivotable about a pin and having asurface inclined with respect to the vertical, said inclined surfacebeing located vertically above one of the abutment elements of thesupport when the distributor is in its rest position, said member goingthrough a sufficient pivoting action about its pivot on the descent ofthe distributor and the driving of the support for said inclined surfaceto be located perpendicularly once more above the following abutmentelement of the support when the lever has been brought back into itsposition of equilibrium on the ascent of the distributor.

4. Device according to claim 3, which comprises abutment surfaces fromthe lever in both its position of equilibrium and its off-set position.

5. Device according to claim 3, wherein the pin about which the lever ispivotable is positioned such with respect to the support that the pointwhere the inclined surface encouners the corresponding abutment elementon the descent of the distributor and the point of contact of theinclined surface with the same element when the support has completedits unitary movement are situated on each side of a vertical planepassing through the pivot of the aforesaid lever.

6. Device according to claim 3, wherein said lever has a form such thatits centre of gravity is raised with respect to its pivot when itundergoes the aforesaid rocking action in the course of the driving ofthe support.

7. Device according to claim 2, wherein the support is constituted by acircular plate adapted to be displaced through unitary angular movementsabout its axis, the samples being disposed on radii of said circularplate at respectively equal distances from its centre, the abutmentelements being constituted by pegs projecting radially from theperiphery of the plate.

8. Device according to claim 1, wherein the rocking member is mounted ona part normally held in a given relative position in relation to thedistributor through the medium of resilient means, said part coming intoabutment with a fixed part of the device before the distributor hasreached its Working position, the distributor being then only able tocomplete its travel in opposition to the action of the aforesaidresilient means.

9. Device according to claim 8, wherein the resilient References CitedUNITED STATES PATENTS 7/1968 Liberti 2l0l98 8/ 19-69 Gourley 74--826 XWILLIAM F. ODEA, Primary Examiner F. D. SHOEMAKER, Assistant ExaminerU.S. Cl. X.R.

